JP2002311173A - Electronic clock, method and program for correcting time error of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic clock which can correct a time error caused by a change in an oscillation frequency due to the temperature of a quartz resonator and which can reduce a power consumption and to provide a method and a program of correcting the time error of the electronic clock. SOLUTION: The electronic clock is provided with a tuning fork-type quartz resonator 101 which corresponds to the operating frequency of a clock IC 103 and whose oscillation frequency is 32.768 kHz, the clock IC 103 which generates time data on the basis of a clock from the quartz resonator 101 and which supplies an interrupt signal at each definite time to a CPU 105, the CPU 105 which rises by responding to the interrupt signal from the clock IC 103, a driver 109 which controls the operation of a time display part 111, the time display part 111 which displays the time and a temperature measuring part 113 which measures a temperature around the quartz resonator 101. The CPU 105 finds the time error on the basis of the temperature measured by the part 113 at each definite time, and it instructs the clock IC to correct the error.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic timepiece, a time error correcting method for an electronic timepiece, and a program for executing the method. Electronic timepiece, a time error correction method for an electronic timepiece, and a time error correction program.

[0002]

2. Description of the Related Art As a conventional electronic timepiece, for example, there is one shown in FIG. The conventional electronic timepiece shown in FIG.
By dividing the clock obtained by the AT crystal unit 51 having the original oscillation frequency of 4.194 MHz by the frequency dividing IC 53, the operating frequency of the clock IC 55 is 32.768.
The frequency is converted to kHz and a clock of this frequency is supplied to the clock IC 55. The clock IC 55 generates time data based on the supplied clock, and sends the time data to the driver 59 via the CPU 57. The time display section 61 displays the time under the control of the driver 59.

In the above-mentioned conventional electronic timepiece, an AT crystal oscillator (high-frequency crystal oscillator) is used as a crystal oscillator, and therefore, an original oscillation frequency of 4.194 MHz is set to a clock IC.
Since the frequency dividing IC 53 is required to convert the frequency to 32.768 kHz, which is the operating frequency of 55, and the clock supplied to the frequency dividing IC 53 is a high frequency of 4.194 MHz, the current consumption increases. There was a problem. Therefore, it is conceivable to adopt a tuning fork type crystal oscillator (low / medium frequency crystal oscillator) having an original oscillation frequency of 32.768 kHz as the crystal oscillator and directly supply a clock of this frequency to the clock IC.

[0004] However, the frequency temperature characteristics of the tuning fork type crystal resonator and the AT crystal resonator are greatly different. As shown in FIG. 6, the tuning fork type crystal resonator (37.768 kHz)
The change of the original vibration frequency due to the temperature change with 5 ° C. as the reference temperature is larger than that of the AT crystal oscillator (4.194 MHz). The change in the original frequency directly affects the time error. For this reason, when using a 37.768 kHz tuning-fork type crystal resonator in which the original vibration frequency greatly changes as the ambient temperature departs from the reference temperature, the temperature around the crystal resonator is measured, and the time error is corrected from the measurement result. It is desirable to do.

[0005]

SUMMARY OF THE INVENTION Accordingly, Japanese Patent Application Laid-Open
As shown in FIG. 7, the electronic timepiece described in Japanese Unexamined Patent Application Publication No. 8-82577 is provided with a temperature measurement unit 7, a storage unit 8, and a correction unit 9, and each time a predetermined time (for example, 24 hours) elapses, the temperature measurement unit 7. The temperature data around the crystal unit 1 measured in step 7 is fetched, and based on the temperature data and the characteristic data in the storage unit 8, a delay time for a predetermined time is calculated and calculated as correction data. The delay is corrected by adding it to the current time data obtained from the integrated circuit 4, and the corrected time data is newly preset in the integrated circuit 4.

However, Japanese Patent Application Laid-Open No. 6-82577 describes
In the publication, there is no description that the temperature measurement unit 7 operates by a trigger such as a start signal, and the correction unit 9 is not described.
Is considered to calculate the correction data based on the temperature data measured by the temperature measurement unit 7 during a certain time. Therefore, the temperature measurement unit 7 must always operate to measure the temperature. However, if the temperature measurement unit 7 always operates, there is a problem that the current consumption increases accordingly.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and it is possible to correct a time error caused by a change in a vibration frequency due to a temperature of a crystal oscillator and to reduce current consumption. It is an object of the present invention to provide an electronic timepiece, a time error correction method for an electronic timepiece, and a time error correction program.

[0008]

In order to solve the above-mentioned problems, an electronic timepiece according to the present invention is an electronic timepiece that divides the time by dividing the frequency of the original oscillation frequency of a quartz oscillator and keeping time. Temperature measuring means for measuring the ambient temperature of the vibrator, and correspondence storage means for storing a correspondence between the temperature of the crystal resonator based on the frequency temperature characteristics of the crystal resonator and the original vibration frequency of the crystal resonator. A time error deriving means for obtaining a time error from the ambient temperature of the crystal unit measured by the temperature measuring means and the correspondence stored in the correspondence storage means, and a time error deriving means. Time correction means for correcting the time based on the time error, and time display means for displaying the time corrected by the time correction means, wherein the time error derivation means is provided at regular intervals. Is moving, to start the said temperature measuring means each time to measure the ambient temperature of the crystal oscillator, and requests the time error.

Further, the electronic timepiece according to the present invention includes an accumulated time error storage means for accumulating and storing the time error obtained by the time error derivation means at every predetermined time, and the time correction means is provided with a predetermined time. When the accumulated time error stored in the accumulated time error storage means exceeds the predetermined time, the time correction means corrects the time error of the predetermined time, and The predetermined time is subtracted from the accumulated time error stored in the time error storage means.

The time error correcting method for an electronic timepiece according to the present invention is a time error correcting method for an electronic timepiece that divides the original oscillation frequency of a quartz oscillator and measures time by counting the time. A temperature measuring step of measuring an ambient temperature of the oscillator, an ambient temperature of the quartz oscillator measured in the temperature measuring step, and a temperature of the quartz oscillator and the quartz based on a frequency temperature characteristic of the quartz oscillator. A time error deriving step of obtaining a time error from the correspondence relationship with the original vibration frequency of the vibrator, and a time correcting step of correcting time based on the time error obtained in the time error deriving step, Are performed at regular time intervals.

Further, the time error correcting method for an electronic timepiece according to the present invention includes a time error accumulating step of accumulating the time error obtained in the time error deriving step for each predetermined time, wherein the time correcting step is performed. When the cumulative time error obtained in the time error accumulating step exceeds a predetermined time, the method further includes a predetermined time subtraction step of correcting the time error of the predetermined time and subtracting the predetermined time from the cumulative time error. is there.

Further, a time error correction program according to the present invention is for causing a computer to execute a time error correction method.

In the electronic timepiece, the time error correcting method and the time error correcting program of the electronic timepiece according to the present invention, the time error deriving means is started at regular time intervals, and the temperature measuring means is started each time (temperature measuring step). Measuring the ambient temperature of the quartz oscillator, and measuring the ambient temperature of the quartz oscillator and the frequency of the quartz oscillator stored in the correspondence memory by the time error deriving means (time error deriving step) A time error is obtained from the correspondence between the temperature of the crystal unit based on the temperature characteristic and the original oscillation frequency of the crystal unit, and the time correction unit (time correction step)
The time is corrected based on the time error obtained by the time error deriving means, and the time corrected by the time correcting means is displayed on the time display means.

Therefore, even if an error occurs in the time due to a change in the ambient temperature of the crystal unit, the error is corrected at regular intervals, so that the accuracy of the time displayed on the time display section is improved. In addition, by stopping the operations of the temperature measuring means and the time error deriving means at times other than the temperature measurement and the time error deriving performed at regular intervals, current consumption can be reduced. Therefore, it is possible to provide an electronic timepiece that displays accurate time and consumes less current.

Further, in the electronic timepiece, the time error correction method and the time error correction program of the electronic timepiece according to the present invention,
The time correction means (time correction step) corrects the time in units of a predetermined time, and the accumulated time error storage means (time error accumulation step) accumulates the time errors obtained at regular intervals, and (Time correction step)
In the above, when the accumulated time error stored in the accumulated time error storage means exceeds a prescribed time, the time error of the prescribed time is corrected, and the prescribed time is subtracted from the accumulated time error.
Therefore, the time can be displayed more accurately.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of an electronic timepiece according to the present invention will be described below in detail with reference to the drawings in the order of [first embodiment] and [second embodiment]. In the description of each embodiment, the electronic timepiece and the time error correction method of the electronic timepiece according to the present invention will be described in detail, but the program according to the present invention is a program for executing the time error correction method. Therefore, the description is included in the following description of the time error correction method.

[First Embodiment] FIG. 1 shows a first embodiment of the present invention.
FIG. 2 is a block diagram showing an electronic timepiece according to the embodiment. Referring to FIG. 1, an electronic timepiece according to the present embodiment includes a crystal oscillator 101 and a clock IC 10 corresponding to a time correcting unit.
3 and C corresponding to the time error deriving means in the claims.
PU 105, CPU crystal unit 107, driver 109, and time display unit 111 corresponding to time display means
A temperature measuring unit 113 corresponding to a temperature measuring unit;
M117 and ROM 117 corresponding to the correspondence storage means
It is comprised including.

The crystal oscillator 101 of the present embodiment has an original oscillation frequency of 3 corresponding to the operating frequency of the clock IC 103.
This is a 2.768 kHz tuning-fork type crystal oscillator (low / medium frequency crystal oscillator). The clock IC 103 includes an oscillation circuit unit (not shown) and a frequency dividing circuit unit (counter circuit unit) therein, and generates time data based on a clock supplied from the crystal unit 101. Further, the clock IC 103 supplies an interrupt signal to the CPU 105 every predetermined time (for example, every one hour).

The CPU 105 determines that the original frequency is 8.
It operates with a clock supplied from the CPU crystal oscillator 107 of 06 MHz, and processes time data obtained from the clock IC 103 to perform data processing on the driver 109.
To send to. The normal CPU 105 is in the low power consumption mode (STOP mode),
, The mode is released by itself, and an activation signal serving as a trigger for activating the temperature measurement unit 113 is supplied to the temperature measurement unit 113. In addition, CPU
When 105 is in the low power consumption mode, the CPU crystal unit 107 is stopped.

The driver 109 controls the operation of the time display unit 111 based on the time data sent from the CPU 105 so that the time display unit 111 displays a desired time. The time display unit 111 is realized by an LCD or the like, and displays time under the control of the driver 109.

The temperature measuring section 113 includes a transistor 121 as a switching means, a fixed resistor R, and a temperature sensor 123 such as a thermistor for measuring the ambient temperature of the crystal unit 101. I have. CP
When a base current (start signal) is supplied from U105 to the base terminal of the transistor 121, the transistor 121
Becomes conductive. When the transistor 121 is turned on,
The power supply voltage VDD is divided by a fixed resistor R and a temperature sensor 123 whose resistance value changes according to the ambient temperature.
A voltage (temperature signal) corresponding to the resistance value of the temperature sensor 123 is applied to 105.

The RAM 115 includes a temperature measuring unit 113
This is a recording medium for temporarily storing temperature data calculated by the CPU 105 based on a temperature signal from the CPU. The ROM 117 stores a program for executing a time error correction method of the electronic timepiece of the present embodiment, which will be described later, and a temperature (T) and a frequency (Δf / f) is a recording medium for storing a table corresponding one-to-one. CPU 105
Represents the temperature data stored in the RAM 115 and the ROM
The frequency (Δf / f) corresponding to the temperature data is determined using the table stored in the memory 117, and a time error is calculated based on the frequency (Δf / f).

The ROM 117 uses a formula for expressing the relationship between the temperature (T) and the frequency (Δf / f) instead of a table in which the temperature (T) and the frequency (Δf / f) correspond one-to-one. May be stored, and the CPU 105 may obtain the frequency (Δf / f) using this calculation formula.

When the CPU 105 calculates the time error, C
The PU 105 sends the clock IC 103 an error correction signal for correcting the time data by the calculated time error.
The clock IC 103 corrects the time data based on the error correction signal and sends it to the CPU 105. As described above, the CPU 105 sends the corrected time data obtained from the clock IC 103 to the driver 109, and the time display unit 111 displays the corrected more accurate time.
Note that the CPU 105 outputs the error correction signal to the clock IC 10.
3, the CPU 105 returns to the low power consumption mode (S
(TOP mode) by software.

Next, a time error correction method performed by the electronic timepiece according to the present embodiment will be described with reference to FIG. First, in step S201, the clock IC 103 sends the
It is determined whether or not an interrupt signal has been supplied to CPU 5, and when the interrupt signal has been supplied, the process proceeds to step S203, and the CPU 1
05 releases the low power consumption mode (STOP mode). Next, in step S205, the CPU 105 supplies a base current to the transistor 121 of the temperature measuring unit 113 to activate the temperature measuring unit 113. Next, step S2
07, the resistance R of the temperature measurement unit 113 and the temperature sensor 12
A signal (temperature signal) having a voltage obtained by dividing the voltage with the signal No. 3 by CP
Supply to U105. Next, in step S209, C
The supply of the base current from the PU 105 to the transistor 121 is stopped.

Next, at step S211, the CPU 10
5 generates temperature data from the temperature signal obtained from the temperature measurement unit, and the temperature (T) and the frequency (Δf / f) correspond one-to-one based on the temperature data and the frequency-temperature characteristics of the crystal unit 101. The frequency (Δf / f) corresponding to the temperature data is determined from the table stored in the ROM 117 and the time error is calculated based on the frequency (Δf / f). Next, in step S213, the CPU
105 sends an error correction signal for correcting the time data by the time error to the clock IC 103.

Next, in step S215, the clock I
C103 corrects the time data based on the sent error correction signal. Thereafter, the CPU 105 sets the clock IC 10
The corrected time data obtained from Step 3
And the time display unit 111 displays the corrected and more accurate time.

As described above, in the electronic timepiece and the time error correction method according to the present embodiment, the temperature measurement unit 113 measures the temperature around the crystal unit 101 at regular time intervals, and
U105 is the quartz oscillator 10 stored in the ROM 117.
(T) and frequency (Δf) based on the frequency-temperature characteristic of
/ F) using a table corresponding one-to-one with the frequency (Δ) corresponding to the temperature data obtained by the temperature measurement unit 113.
f / f), and the time difference error is calculated based on the frequency (Δf / f). When the time error is calculated by the CPU 105, an error correction signal for correcting the time data by the calculated time error is output to the clock IC 10.
The clock IC 103 corrects the time data based on the error correction signal. Therefore, even if an error occurs in the time due to a change in the ambient temperature of the crystal unit 101, the error is corrected at regular time intervals.
The accuracy of the time displayed in 1 is improved.

During a period other than the temperature measurement and the time error calculation performed at regular intervals, the CPU 105 is in the low power consumption mode (STOP mode) and the crystal unit 107 for the CPU is in a stopped state. Can be reduced. Therefore, it is possible to provide an electronic timepiece that displays accurate time and consumes less current.

[Second Embodiment] The electronic timepiece of the second embodiment has substantially the same configuration as the electronic timepiece of the first embodiment. However, the ROM 117 stores a program for executing a time error correction method for an electronic timepiece according to the present embodiment described later. In addition, the RAM 115 corresponding to the accumulated time error storage means in the claims includes a CPU 10.
The time error (time error data) calculated in step 5 is stored, and a cumulative value of the time error described later is stored.
Hereinafter, the time error correction method of the electronic timepiece according to the present embodiment will be described with reference to FIGS. 3 and 4
5 is a flowchart illustrating a time error correction method for an electronic timepiece according to a second embodiment of the present invention. In the figure,
Steps that are the same as those in FIG. 2 (first embodiment) are given the same reference numerals, and descriptions thereof are omitted.

As shown in FIG. 3 and FIG.
As shown in 201 to S211, the temperature around the crystal unit 101 is measured by the temperature measurement unit 113 at regular time intervals, and the CP
U105 is the quartz oscillator 10 stored in the ROM 117.
(T) and frequency (Δf) based on the frequency-temperature characteristic of
/ F) using a table corresponding one-to-one with the frequency (Δ) corresponding to the temperature data obtained by the temperature measurement unit 113.
f / f), and the time difference error is calculated based on the frequency (Δf / f).

When the time error is calculated in step S211, the calculated time error value is added to the integrated error value stored in the RAM 115 in step S301. Next, in step S303, it is determined whether or not the integrated value has exceeded one second.
To step S305. In step S305, the CPU 105 sends an error correction signal for one second to the clock IC 103. Next, step S215
Then, the clock IC 103 corrects the time data based on the sent error correction signal. Next, step S307
Then, step S211 stored in the RAM 115 is executed.
One second is subtracted from the integrated error value integrated in the step.

As described above, in the electronic timepiece and the time error correction method of the present embodiment, the time error is calculated at regular intervals, and the value obtained by integrating this value with the integrated error value stored in the RAM 115 is Since the time data is corrected in units of one second when the time exceeds one second, the time can be displayed more accurately. In the present embodiment, the unit for correcting the time error is 1 second, but may be 2 seconds, 10 seconds, or 1 minute.

[0034]

As described above, according to the electronic timepiece, the time error correcting method of the electronic timepiece, and the time error correcting program of the present invention, the time error deriving means is started at regular intervals, and each time the temperature is measured. The means is started (at the temperature measuring step) to measure the ambient temperature of the quartz oscillator, and at the time error deriving means (time error deriving step), the measured ambient temperature of the quartz oscillator is stored in the correspondence storage means. A time error is obtained from the stored relationship between the temperature of the crystal unit based on the frequency temperature characteristics of the crystal unit and the original oscillation frequency of the crystal unit, and the time correction unit (time correction step) The time is corrected based on the time error obtained by the error deriving means, and the time corrected by the time correcting means is displayed on the time display means.

Therefore, even if an error occurs in the time due to a change in the ambient temperature of the crystal unit 101, the error is corrected at regular intervals, so that the accuracy of the time displayed on the time display unit 111 is improved. In addition, by stopping the operations of the temperature measuring means and the time error deriving means at times other than the temperature measurement and the time error deriving performed at regular intervals, current consumption can be reduced. Therefore, it is possible to provide an electronic timepiece that displays accurate time and consumes less current.

Further, in the electronic timepiece, the time error correction method and the time error correction program of the electronic timepiece according to the present invention,
The time correction means (time correction step) corrects the time in units of a predetermined time, and the accumulated time error storage means (time error accumulation step) accumulates the time errors obtained at regular intervals, and (Time correction step)
In the above, when the accumulated time error stored in the accumulated time error storage means exceeds a prescribed time, the time error of the prescribed time is corrected, and the prescribed time is subtracted from the accumulated time error.
Therefore, the time can be displayed more accurately.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an electronic timepiece according to a first embodiment of the present invention.

FIG. 2 is a flowchart illustrating a time error correction method of the electronic timepiece according to the first embodiment of the present invention.

FIG. 3 is a flowchart illustrating a time error correction method for an electronic timepiece according to a second embodiment of the present invention.

FIG. 4 is a continuation of the flowchart showing the time error correction method for the electronic timepiece according to the first embodiment of the present invention.

FIG. 5 is a block diagram showing a conventional electronic timepiece.

FIG. 6 is an explanatory diagram showing frequency temperature characteristics of a tuning fork type crystal unit and an AT crystal unit.

FIG. 7 is a block diagram showing an electronic timepiece described in JP-A-6-82577.

[Explanation of symbols]

 101 Crystal Resonator 103 Clock IC 105 CPU 107 CPU Crystal Resonator 109 Driver 111 Time Display Unit 113 Temperature Measurement Unit 115 RAM 117 ROM 121 Transistor 123 Temperature Sensor R Fixed Resistance

Continued on the front page F-term (reference) 2F002 AA07 AD06 AD07 DA00 FA10 GA04

Claims (5)

[Claims] 1. An electronic timepiece which divides the time by dividing the frequency of an original oscillation of a crystal unit and keeping time by measuring the frequency. 9. A temperature measuring means for measuring an ambient temperature of the crystal unit, and a frequency and temperature of the crystal unit. Correspondence storage means for storing a correspondence between the temperature of the crystal resonator based on the characteristic and the original vibration frequency of the crystal resonator, and the correspondence between the ambient temperature of the crystal resonator measured by the temperature measurement means. A time error deriving means for obtaining a time error from the correspondence stored in the storage means, a time correcting means for correcting a time based on the time error obtained by the time error deriving means, and the time correcting means Time display means for displaying the corrected time, wherein the time error derivation means is activated at regular intervals, and each time the temperature measurement means is activated to activate the periphery of the crystal unit. An electronic timepiece which measures an ambient temperature and obtains the time error. 2. The apparatus according to claim 1, further comprising: an accumulative time error storage unit that accumulates and stores the time error obtained by the time error derivation unit for each predetermined time, wherein the time correction unit corrects the time by a predetermined time unit. When the accumulated time error stored in the accumulated time error storage means exceeds the predetermined time, the time correction means corrects the time error of the predetermined time, and is stored in the accumulated time error storage means. 2. The electronic timepiece according to claim 1, wherein the predetermined time is subtracted from the accumulated time error. 3. A time error correction method for an electronic timepiece that divides a time by dividing and dividing a frequency of an original vibration of a crystal unit, comprising: a temperature measuring step of measuring an ambient temperature of the crystal unit; Ambient temperature of the crystal unit measured in the temperature measurement step, based on the frequency temperature characteristics of the crystal unit,
A time error deriving step of obtaining a time error from the correspondence between the temperature of the crystal resonator and the original vibration frequency of the crystal resonator, and a time for correcting the time based on the time error obtained in the time error derivation step. A time error correction method, comprising: a correction step; and performing these steps at regular intervals. 4. A time error accumulating step for accumulating a time error obtained in the time error deriving step for each fixed time, wherein the time correcting step includes a step of accumulating the time error obtained in the time error accumulating step. 4. The time error correction method according to claim 3, further comprising the step of: correcting a time error of the predetermined time when the time exceeds a predetermined time, and subtracting the predetermined time from the accumulated time error. 5. A time error correction program for causing a computer to execute the time error correction method for an electronic timepiece according to claim 3.